The Bad Astronomer writes: "A new study finds that there may be 100 billion alien planets in the Milky Way alone, with 17 billion of them the size of Earth. Announcements like this have been made before, but this new research is more robust than previous studies, using data from the Kepler planet-hunting spacecraft over a longer period and analyzing it in a more statistically solid way. They also found that smaller planets are not as picky about their host stars, with terrestrial planets forming around stars like the Sun or as small as tiny, cool red dwarfs with equal ease."